What can happen if i didnt change my brake fluid ?

 

Dot 3 and 4 is hydroscopic and absorbs water. Over time it can cause rust in your brake system. Dot 5 is used in some years. It is not supposed to do this but brake fluid should be changed periodically to keep your brakes in good working order.

 

Perfect answer. If you buy one of those cheap vacum / brake bleeders from the auto store that you hook to your bleed screws and suck the fluid out with, you can do both in about 20 minutes.

 

What if i dont change at all.
What would fail first out of the brake system ?

 

You would probably fail first when you roll through the red light at an intersection.

 

Bro im being serious cuz i have a weird problem in my brake

 

Is it leaking? Check the seals in the caliper.
If it's seized try taking off the caliper and seeing if the pads float freely. If the piston won't go back in then the caliper is probably shot. If the master cylinder isn't building pressure then that's shot. Is the foot peddle stuck down and it didn't return to it's proper position? Maybe that needs some lube?

 

The problem is when i move the bike a few feet the bike feels like the brake is being pressed and pressure in the brake paddle is gone. I press the paddle a couple time then pressure starts to build up.

 

Like said, water or air in the brake line will give you brake fade, a rusty piston will prevent it from moving.

 

Your best start at resolving your problem is to change your brake fluid - ASAP. As previously stated, it is easy and inexpensive. Flush it well and refill, bleed them, and you'll likely be in good shape.